Becoming a face expert

我研究的目的是了解人类发展的机制。为此，我研究了视觉感知的发展及其在视觉经验变化中的改变。本方案的重点是人脸处理。成年人是识别单个面孔的专家，很大程度上是因为他们对面部特征间距上的细微差异非常敏感。这种敏感性使他们能够从不同的角度，在光线不足的情况下，以及在多年过去和脸部老化之后识别人脸。这种专业知识的成熟是缓慢的：14岁的孩子和成年人不一样，4岁的孩子甚至不能认出自己的脸，当它与一张只有五官间距不同的陪衬脸搭配在一起时。我将通过两个研究项目调查经验在专业知识发展中的作用。第一个重点是学龄前的面部感知，这一时期还没有被系统地研究过。我将测试多种面部处理机制对面部特征间距敏感的假设，并且这些机制以不同的速度发展。例如，我将比较儿童对不熟悉面孔和熟悉面孔（例如，玩伴）特征间距的敏感性。第二部分侧重于经验的自然变化对专业知识发展的作用。成年人比其他种族的人更善于识别自己种族的面孔，因此他们的专长仅限于他们有丰富经验的面孔。我将使用三种互补的方法来调查经验的作用：a)我将对外国交换学生（例如，到达加拿大的中国学生）的新种族面孔的专业知识发展进行纵向研究；b)我将比较主要接触到自己种族面孔的儿童与从中国收养的儿童，他们广泛接触到白人和中国人的面孔；c)我将测试具有非人类（猴子）面孔专业知识的成年人，因为他们是动物园的管理员。总之，这些结果将增加我们对人类视觉感知和发展机制的理解。

The objective of my research is to understand the mechanisms of human development. To do so, I study the development of visual perception and its alteration by variations in visual experience. This proposal focuses on face processing. Adults are experts at recognizing the identity of individual faces, largely because they are exquisitely sensitive to small differences among faces in the spacing of facial features. This sensitivity allows them to recognize faces from different points of view, under poor lighting conditions, and after many years have passed and the face has aged. This expertise is slow to mature: 14-year-olds are not adultlike and 4-year-olds cannot recognize even their own face when it is paired with a foil face that differs only in the spacing of features. I will investigate the role of experience in the development of expertise through two research programs. The first focuses on face perception during the pre-school years, a time period that has not been studied systematically. I will test the hypothesis that multiple face-processing mechanisms are sensitive to the spacing of facial features and that these mechanisms develop at different rates. For example, I will compare children's sensitivity to the spacing of features in unfamiliar versus familiar (e.g., a playmate) faces. The second focuses on the role of natural variations in experience on the development of expertise. Adults are better at recognizing own-race faces than other-race faces, thus their expertise is limited to faces with which they have abundant experience. I will investigate the role of experience using three complementary approaches: a) I will conduct a longitudinal study of the development of expertise for a new race of faces in foreign exchange students (e.g., Chinese students arriving in Canada); b) I will compare children who are exposed primarily to own-race faces with children adopted from China who receive extensive exposure to Caucasian and Chinese faces; and c) I will test adults with expertise with nonhuman (monkey) faces because they are curators at a zoo. Together, the results will add to our understanding of human visual perception and of developmental mechanisms.